Course-finder



. C. N. WESTWOOD.

COURSE FINDER. APPLICATION FILED II'IIIE 23'.AI;9I9.

1,350,58 1 .l Patented Aug. 24, 1920.

anim/nui CORAL NOVELL() WESTWOOD, 0F VICTORIA, BRITISH COLUMBIA, CANADA.

Specification of Letters Patent.

COURSE-FINDER.

.Patented All?. 24,1920.

Application filed June 23, 1919. Serial No. 306,140.

To all 007mm t may concern.' Y

Be it known that I, CORAL NovELLo fusaiwoon, a subject ofthe ling of Great Britain, and a resident ot Victoria, British Columbia, Canada, have invented a newv and useful Improvement inV Course-Finders, of which the following is a specification.

'My invention is an improvement in course finders and has for its object to provide an instrument of the character specied by means of which in connectionv with a chart courses may be easily found and corrected.

in the drawings Figure 1 is a side view of the improved instrument with parts in section,

Fig. 2 is a top plan View,

F ig. 3 is a perspective view ot the slide, and

Fig. 4E is a similar view of the elongated washer. l

lnY the present embodiment oi the invention a blade 1 is provided of suitable material and dimensions, and at one end ot this blade is an opening'Q for permitting the instrument to be suspended and a gage mark 3 is drawn squarely across the blade a slight distance from the opening. A slide l is mounted upon the blade, the said slide having underlying flanges engaging beneath the blade as shown in Fig. 3, and this slide has a central boss 5 Vwhich is internally threaded for engagemen'r by a set screw 6 to hold the slidein adjusted position. lfiwhen the slide -1- is used in. conjunction with the gage line 3 in measuring distances, the set screw engages the blade. YA,v plate spring 7 is secured to the slide at: that end adjacent to the opening 2 and the said spring entends beyond the slide into contact with the blade,

the arrangement being such that when the slide is moyed far 'enough toward the end of the plate spring 7 will engage within the opening Q'to prevent the slide moving entirely Oft the blade. At the opposite end from the spring and at vone side there is pro- Y vided Va perforated lug S'extending laterally from the slide, the said lug being adapted to permit the point of a pencil to be passed through the hole onto thechart for pivoting and holding, by means of the slide,

-vthe edge of the blade over any'particular point while the instrument is set and placed', on any desired course or angle when tracing or laying off a course on a chart, 'and the lines drawn along the edge of the blade from such point.

Near the opposite end a hollow hub 9 is held within an opening in the blade, and within the hub at the level ot the blade is arranged a transparent plate 10, the said plate being o1" glass or other transparent material and this plate has at its center a fixed dot or marit to indicate the center for centering the instrument over any point. A mariners compass card 11 is mounted to rotate on the hub adjacent to the blade and above this card is arranged a ring l2 having four arms 13, the said arms being pointed as shown, and constituting with the ring a four-pointed star and the points of the star are `arranged at angles of 900 with respect to each other and one of the arms bears the letter N formed upon the upper surface thereof in any suitable or desired manner. Above the ring 12 a collar 14 encircles the hub and this collar has a single pointer 15 extending to the outermost scale ot the compass card as do also the arms 13. These elements, namely, the card, the ring and the collar, are held in place on the hub by means of a split resilient ring 1G clamped about the hub above the collar, and it will be noticed that the upper end of the hub has an angular groove cut into it, into which the ring is sprung and, contracting in the groove, holds all the revolving parts frictionally tight on the hub by pressing down ot collar 14. The collar may be clamped on the hub by means of set screw 17 which is threaded through a boss on the collar in engagement with the hub.

The four-pointed star ma. beclamped to the compass card by means ot a set screw 18 which passes through an arc shaped slot 19 in the ring 1Q into engagement with the car-d. A washer 2O enrircles this set screw above the-ring 12 and this washer has a radial lug 2 1 which overlies an outwardly extending lange at the lower end of the collar. Hence when the washer 20 is placed inproper position and the set screw 18 is turned in the proper direction the compass card andthe tour-pointed star will not only be clamped together but the collar will also be clamped to the star. An arc shaped guide 23 is rigidly fastened to the blade and by means ot' a threaded stem 2l and a thumb nut 25, the threaded stem being rigid with the blade and passing through an opening in a lug at the center of the convex edge of the guide and beino engaged by the thumb nut above the guide, and by means of the thumb indicator 28 which is rigidly fastened to the' center oi the blade. l

The mariners. compass card is graduated from naught to ninety, from north and south to east and west, also from zero at the northpoint to the right or to the east to 359 in consecutive .order,indicating figures being placed at, say, everyy 100. The card is other wise the ordinary and usual Vmariners compass card.

lnth'e use of the elements shownat the lett of-Figs. 1 and 2, the slide a may be clamped at any desired point on'tlie blade when the slide is used together with the gage line 3 in measuring distances.

Yln operation, assuming that aY chart has a variation of 25O east and that the points 13 of the instrument are coincident with the four cardinal points vof the compass card. instrument isV placed with the blade away from the user, the card is then rotated until the iT coincidesvwith the poiiitor indicator 28 of the blade,this point being'at the center of the blade. p The clamping screw 18 is now loosened and thel four-pointed star is rotated to the west o'-th'e compass card until @that point oit the 'four pointed stai' bearing the mark N is 25.D west of the N on the com-' pass card, after which the clampingscrew 13 is tightened to clamp the partsr together.

(In allowing for eastvariation the point N on the four-pointed star is always set to the west and always to the east for west variation.) VNow place the blade of the instrumenton the chart in the direction of the course required, hold the slide e irmly on the chart while the compass is moved onto the most convenient line of parallel or meridian, by placing the dot, at the center of the plate 10, immediately on such line, then the compass is` rotated, always keeping the' v north of the compass to the northerly portion of the chart until twoopl'iosite points of the four-pointed star come into parallelism with the line over which the dot in the plate 10 has been placed. The course is now read' v on the compass. at the point 28, this being ther correct magnetic course to steer by a compass having no deviation, and for use inthe following vexample we will assume that the i course-is N. 29 l/V. 'x i Suppose a coinpasshas a deviation of 6"y east and it is desired to` steer by it an equal course tothe one above, that is, N. 29o W.

The

(Thervariations are not needed in this operation but may remain set up on the instrument.) By placing the point 27 on the slide 26 which is at the top of Fig. 2, 6 east of the point 28 and then bringing the course N.

429o W'. to this point 27 there willbe read VN. 35 W7., the courserequired.

It the deviation had .been 6-0 lwest then the point 27 at the bottom of the slide 26'would have been moved `V west and the course R290 WV. moved tofthispoint 27 and the course required,rN. 23 WV., would be read at the point 28 as before. l

By reversing the operation the courses are corrected to magnetic. Take, Jfor instance, the course last mentioned, N. 23 W., having a deviation of '6 west, which, reversed, would be 6o east,.the point 27 at the top oi" the slide 26V would be 'placed' 60 east of the point 28, and the course N. 23 WV. would be brought to itand then read the magnetic course of N. 290 W., the assumed course obtained by the {irst example with a variation of 25o east. Y V

All courses by deviating Compasses should be corrected to magnetic it' to be traced on a chart under proper variation of place by Vthe instrument, by aid of the lug 8.

Thepointer 15 when used in conjunction with the point 28 to iindthe true courses Vfrom the magnetic ones is placed at the exact number of Ydegrees of variation but in the opposite direction, that is, for west variation the pointer is `set to the east, and for east variation the pointer is set to the west. W hen the pointer 15 isused as an indicator of the direction of'tide's, currents or wind,

relative to the course being steered, it is released from the hub 9 and isfclamp'ed to the four-pointed star 12 byV vplacing'the lug of the washer 2O over the flange of the collar 14. The pointer is then set to the direction from which the wind is coming and on the compasscard the angle between the pointer and the course can be read olf from time to time as the course-'maybe changed should the windY continue from the same direction and leeward allowed accordingly.

I claim Y' v 1. A device of theY character specified, comprising a bladeya hub'near one end of the blade, a mariners compass card mounted to vrotate on the hub, a ring having pointers extending at angles of ninety degrees Y mounted on the hublabove the card, a pointer journaled en the hub'above the ring to rotate thereon,"means for clamping thepointer to the hub, means for clamping the'ring to Vthe cardiand having means for clamping the pointer to the ring when desired, a YXed indicatoren theblade, and a pair of indicators spaced apart from eachother-and arranged Von'opposite sides of the irst-named indicator and simultaneously adjustable with respect thereto.

2. device of the character specified, comprising a blade, a hub near one end of the blade, a mariners compass card mounted to rotate on the hub, a ring having pointers extending at angles of ninety degrees mounted on the hub above the card :and cooperating therewith, a pointer journaled on the hub above the ring to rotate thereon, means for clamping the pointer to the hub, means for clamping the ring to the card, and having moans for clamping the pointer to the ring when desired, a fixed indicator on the blade, and a pair of'yindicators fixed with respect to each other and adjustable simultaneously with respect to the first named indicator laterally of the blade.

3. A device of the character specified, comprising a blade, ahub near one end of the blade, a mariners compass card mounted to rotate on the hub, a ring having pointers extending` at angles of ninety degrees mounted on the hub above the card and cooperating therewith, means for clamping the ring to the card, a fixed indicator on the blade, and a pair of indicators fixed with respect to each other and adjustable simultaneously with respect to the first named indicator laterally of the blade.

a. A device of' the character specified comprising a blade, a mariners compass card mounted to rotate on the blade, a fixed indicator on the blade coperating with the compass card, an arc shaped bar adjustable transversely of the blade and carrying indicators at its ends coperating with the card, ring having points arranged at angles of ninety degrees with respect to each other rotatable on the blade at the axis of' the card, means for fixing the ring and the compass with respect to the blade, a pointer mounted to swing about the axis of the card, and means in connection with the fixing means of the card and ring for fixing also the pointer.

5. A device of the character specified comprising a blade, a mariners compass card mounted to rotate on the blade, a fixed indicator on the blade coperating with the compass card, an arc shaped bar adjustable transversely of the blade and carrying indicators at its ends coperating with the card, a ring having points arranged at angles of ninety degrees with respect to each other rotatable on the blade at the axis of the card, and means for fixing the ring and the compass with respect to the blade.

6. A device of' the character specified comprising a blade, a mariners compass card mounted to rotate on the blade, a fixed indicator on the blade cooperating with the compass card, and an arc shaped bar adjustable transverselv of the blade and carrying indicators at its ends coperating with the card.

7. A device of the character specified, a blade, a slide mounted to move longitudinally of the blade, means for fixing the slide, and means for preventing accidental displacement of the slide from the blade, said means comprising an opening in the blade and a spring on the slide and adapted to engage the opening when the slide is near the end of the blade.

8. In an instrument of the character specified, a blade having at one end a hub and indicating mechanism mounted to rotate on the hub, said mechanism including a sleeve encircling the hub, the hub having an annular groove near its upper end and a split ring in the groove and engaging the upper end of the sleeve, said groove and ring having cooperating cam surfaces for forcing the ring downwardly.

9. A device or" the character specified comprising a blade, a mariners compass card mounted to rotate on the blade, a fixed indicator on the blade cooperating with the compass card, and a bar adjustable trans versely of the blade and carrying indicators at its ends cooperating with the card.

CORAL NovnLLo wEsTwooD. 

